/**
 * 乐扣地址：https://leetcode-cn.com/problems/palindrome-number/
 */
var isPalindrome = function(x) {
    if(x < 0) return false
    if(x < 10) return true
    const numStr = x + ''
    const l = numStr.length
    let start = 0
    let end  = l - 1
    while(start < end){
       if(numStr[start] === numStr[end]){
        start++
        end--
       }else{
         return false
       }
    }
    return true
};
isPalindrome(121)